running transactions in postgresql

hi,

 Iam working on project that deals with analyzing the locking mechanism in postgresql.

I started a transaction in postgresql with 'begin work;' and noticed that even though no locks have been taken yet, there still exists data in LockData datastructures that indicates that the transaction i just started running is waiting for a lock.Does anyone know why this happens? I f not , could someone guide me to the appropriate site or mailinglist where my question can be answered.

thank you

Jenny